浙江省宁波地区登革热疫情前后白纹伊蚊抗药性调查

Comparison of insecticide resistance of Aedes albopictus before and after dengue fever epidemic in Ningbo,Zhejiang

目的调查浙江省宁波地区登革热疫情前后白纹伊蚊对常用杀虫剂的抗药性变化,为抗药性治理和登革热防控提供科学依据。方法登革热疫情发生前(2018年)在宁波市辖10个县(市、区)采集白纹伊蚊幼蚊,疫情发生后(2019年)在登革热旧疫点采集白纹伊蚊幼蚊。采集的幼蚊在实验室繁殖1~2代,分别采用浸渍法和接触法测定幼蚊和成蚊抗药性。结果2018年,白纹伊蚊幼蚊对溴氰菊酯、高效氯氰菊酯、残杀威、敌敌畏和双硫磷的抗性倍数分别为45.43、18.85、4.81、1.55和4.13,2019年抗性倍数分别为82.00、29.43、7.14、3.27和6.25。将白纹伊蚊成蚊暴露于0.4%高效氯氰菊酯、0.1%溴氰菊酯、3%氯菊酯、0.05%残杀威和0.5%马拉硫磷各1 h,2018年试虫24 h死亡率分别为98.33%、83.33%、88.52%、95.24%和76.67%,2019年试虫24 h死亡率分别为98.89%、92.22%、98.89%、100.00%和98.89%。结论宁波地区白纹伊蚊幼蚊对测试的杀虫剂均产生了抗药性,且较登革热疫情前有了较大提高,而成蚊对测试的杀虫剂则相对敏感,抗药性未出现明显提高。幼蚊和成蚊对杀虫剂的抗性水平并不一致,蚊虫防控应根据不同虫态的抗药性采取相应杀虫剂使用策略。

Objective To investigate the resistance of Aedes albopictus to common insecticides before and after the dengue fever epidemic in Ningbo,Zhejiang province,and provide a scientific evidence for resistance management and dengue fever control.Methods Ae.albopictus larvae were collected in 10 counties(districts)in Ningbo before the epidemic of dengue fever in 2018 and after the epidemic in 2019.The collected larvae were reared for 1–2 generations in laboratory.The resistance of larvae and adults was determined by dipping method and contact method,respectively.Results The resistance ratios of Ae.albopictus larvae to deltamethrin,beta-cypermethrin,propoxur,dichlorvos and temephos were 45.43,18.85,4.81,1.55 and 4.13 in 2018,respectively,and 82.00,29.43,7.14,3.27 and 6.25 in 2019,respectively.Ae.albopictus adults exposed to 0.4%beta-cypermethrin,0.1%deltamethrin,3%permethrin,0.05%propoxur and 0.5%malathion for 1 h,the death rates were 98.33%,83.33%,88.52%,95.24%and 76.67%24 h later in 2018,respectively,and 98.89%,92.22%,98.89%,100.00%and 98.89%24 h later in 2019,respectively.Conclusion Ae.albopictus larvae in Ningbo developed resistance to the tested insecticides,which was significantly higher than that before the dengue fever epidemic.While adult mosquitoes were relatively sensitive to the tested insecticides,and the resistance did not significantly increase.The insecticide resistance levels of larvae and adult mosquitoes were not consistent,so appropriate insecticide use strategies should be adopted for mosquito control according to the insecticide resistance of Ae.albopictus at different growth stage.